There are two depressing take-aways (maybe a lot more) from the excellent article: it can cost $500,000 to enforce a copyright through discovery and trial, and content owners must constantly monitor the use of their work online.

For the latter, I subscribe to Blasty's full service, but to date there are over 1957 instances where Google's lawyers have determined (erroneously IMHO) that the "libraries" offering ebook versions of my works are entitled to do so.